Quantum mechanics

Magnetic field

Voltage

Engineering

Faraday cage

MATLAB

Electrochemistry

Materials science

Embedded system

Polymer electrolyte membrane electrolysis

Operating system

Computer science

Physical chemistry

Polarization (electrochemistry)

Hydrogen

Physics

Nuclear engineering

Organic chemistry

Simulation

Empirical modelling

Alkaline water electrolysis

Environmental science

Data science

Chemistry

Electrode

Electrolyte

Electrolysis

Test bench

Model validation

Electrical engineering

International Journal of Hydrogen Energy

This paper presents a semi-empirical mathematical model for predicting the electrochemical behavior of an alkaline water electrolysis system, based on the polarization curve and Faraday efficiency as a function of the current density under different operating conditions, such as, temperature and pressure. Also, the gas impurities of hydrogen in oxygen have been modeled for safety reasons due to its importance when the electrolyzer is dynamically operated using renewable energy sources. The different parameters defined in the model have been calculated by MATLAB, using a non-linear regression, on the basis of experimental data obtained in a 15 kW alkaline test bench. The simulated and measured values have been compared to ensure the accuracy and validity of the proposed model. In this sense, the error has been evaluated for the voltage with an average result of 5.67 mV per cell and for the Faraday efficiency and the gas impurities of hydrogen in oxygen with a value lower than 1%. These results show an excellent correlation between experimental and modeled data, so the model is a useful design and optimization tool for alkaline electrolyzers. Also, a sensitivity analysis has been used to determine the most influential operating variables in the performance of the electrolyzer.

Semi-empirical model and experimental validation for the performance evaluation of a 15 kW alkaline water electrolyzer